In certain conventional type pneumatic punch press feeders control circuits have been used to automatically trigger a feed stroke of the feed slide in response the completion of an index stroke thereof and vice versa; however these control circuits utilize limit switches for sensing for the physical presence of the feed slide when the latter has arrived at the end of one or both of said strokes. One of the difficulties associated with this type of sensing arrangement is that the limit switch means must be positionally adjustable for accommodating different positional limits desired for the end of one or both of said strokes as is required where different feed stroke lengths of the feeder are desired. This condition necessitates not only an adjustable mounting for the limit switch type sensing means but also requires that the circuit connections between said adjustable limit switch sensing means and the remaining portions of the control system be flexible or otherwise adjustable so as to accommodate the said adjustable positionment of one or both of said limit switch means. These requirements can cause practical set-up difficulties, particularly where the sensing means must be installed near an extreme longitudinal end of the feeder and loose and cumbersome circuit tubing and/or other control interconnections must be maintained therewith to accommodate the remote and required adjustable positionment of said sensing means.
The principle object of the present invention is to provide a novel pressure sensing arrangement for controlling the automatic reversal of operative movement of the feed slide in a pneumatically operated punch press feeder.
Another object of the invention is to provide an improved pneumatic feeder having control means for controlling the automatic initiation of the next operative stroke of the feed slide thereof whereby no positional adjustment is required for said control means for different feed stroke lengths of said feeder.
Another object of the invention is to provide a pneumatically operated feeder for punch presses and the like having a reciprocable feed slide and wherein the effective fluid pressure in the fluid motor for actuating the feed slide is sensed in order to determine when one operative stroke of the feed slide has been completed and to initiate a signal in response thereto so as to cause initiation of the next operative stroke of said feed slide.
A further object of the invention is to provide a novel single feed slide type pneumatic feeder having an improved control means which when operated is adapted to cause the feed slide to automatically partake of a plurality of successive feed strokes.
Other objects of the invention will become apparent as the disclosure progresses.